As far as life of the WB, I suppose it depends on which one the setup uses. I have both a Innovate LM1 and the Dual FAST setup like in the first post.
The LM1 uses a wb sensor that is used in a new VW and should last very long since it is standard equip on VW's. The LM1 is permanently installed in my GN and it controls fueling based solely on the AFR programmed into it, so the wb provided that feedback to adjust fueling.
Just program in the AFR you want at what rpms ranges and go...when the methanol kicks in, the fueling is auto adjusted...if for some reason the meth pump fails, the setup sees it go lean and adds fuel instantly.

The dual FAST setup I use from car to car for tuning only. Never had a problem with either setup and the FAST setup can record and playback without a laptop unlike the LM1.